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Create a table from CSV columns in SQL Server without using a cursor

Given a table:

|Name    | Hobbies                |
-----------------------------------
|Joe     | Eating,Running,Golf    |
|Dafydd  | Swimming,Coding,Gaming |

I would like to split these rows out to get:

|Name    | Hobby     |
----------------------
|Joe     | Eating    |
|Joe     | Running   |
|Joe     | Golf      |
|Dafydd  | Swimming  |
|Dafydd  | Coding    |
|Dafydd  | Gaming    |

I have completed this below (example is ready to run in SSMS), buy my solution uses a cursor which I think is ugly. Is there a better way of doing this? I am on SQL Server 2008 R2 if there is anything new which will help me.

Thanks

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[Split]') and xtype in (N'FN', N'IF', N'TF')) drop function [dbo].Split
go
CREATE FUNCTION dbo.Split (@sep char(1), @s varchar(512))
RETURNS table
AS
RETURN (
    WITH Pieces(pn, start, stop) AS (
      SELECT 1, 1, CHARINDEX(@sep, @s)
      UNION ALL
      SELECT pn + 1, stop + 1, CHARINDEX(@sep, @s, stop + 1)
      FROM Pieces
      WHERE stop > 0
    )
    SELECT pn,
      SUBSTRING(@s, start, CASE WHEN stop > 0 THEN stop-start ELSE 512 END) AS s
    FROM Pieces
  )


go

declare @inputtable table (
    name varchar(200) not null,
    hobbies varchar(200) not null
)

declare @outputtable table (
    name varchar(200) not null,
    hobby varchar(200) not null
)

insert into @inputtable values('Joe', 'Eating,Running,Golf')
insert into @inputtable values('Dafydd', 'Swimming,Coding,Gaming')

select * from @inputtable

declare inputcursor cursor for
select name, hobbies
from @inputtable

open inputcursor

declare @name varchar(255), @hobbiescsv varchar(255)
fetch next from inputcursor into @name, @hobbiescsv
while(@@FETCH_STATUS <> -1) begin

    insert into @outputtable
    select @name, splithobbies.s
    from dbo.split(',', @hobbiescsv) splithobbies

    fetch next from inputcursor into @name, @hobbiescsv 
end
close inputcursor
deallocate inputcursor

select * from @outputtable
like image 560
amarsuperstar Avatar asked Sep 07 '10 16:09

amarsuperstar


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1 Answers

Use a string parsing function like the one found here. The key is to use CROSS APPLY to execute the function for each row in your base table.

CREATE FUNCTION [dbo].[fnParseStringTSQL] (@string NVARCHAR(MAX),@separator NCHAR(1))
RETURNS @parsedString TABLE (string NVARCHAR(MAX))
AS 
BEGIN
   DECLARE @position int
   SET @position = 1
   SET @string = @string + @separator
   WHILE charindex(@separator,@string,@position) <> 0
      BEGIN
         INSERT into @parsedString
         SELECT substring(@string, @position, charindex(@separator,@string,@position) - @position)
         SET @position = charindex(@separator,@string,@position) + 1
      END
     RETURN
END
go

declare @MyTable table (
    Name char(10),
    Hobbies varchar(100)
)

insert into @MyTable
    (Name, Hobbies)
    select 'Joe', 'Eating,Running,Golf'
    union all
    select 'Dafydd', 'Swimming,Coding,Gaming'

select t.Name, p.String
    from @mytable t
        cross apply dbo.fnParseStringTSQL(t.Hobbies, ',') p

DROP FUNCTION [dbo].[fnParseStringTSQL]
like image 122
Joe Stefanelli Avatar answered Oct 23 '22 05:10

Joe Stefanelli